Ascent 900 Down Sleeping Bag (-18C)
A very warm, 650FP duck down sleeping bag with a recycled, wind-resistant Pertex® Quantum outer. Designed with a comfortable wide shape, it's ideal for those buying their first down sleeping bag for use in cold, winter conditions.
Product Characteristics
What It's Best For
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The Specifics
- Weight:(Regular) 1530g/54.0oz, (Long) 1610g/56.8oz
- Rab Sleep Limit:Rab Sleep Limit: -18°C (0°F)
- Product Code:QSD-39
- 30D Recycled Pertex® Quantum (50gsm) with fluorocarbon-free DWR
- Lining: 20D Recycled Nylon (38gsm)
- 650FP European Duck Down with Nikwax Fluorocarbon-Free Hydrophobic Finish (900g / 31.7oz)
- Trapezoidal boxwall construction, to maximise loft and warmth
- 3-dimensional shaped neck collar to seal in warmth
- YKK 3/4 length main zip with down filled baffle to trap warmth
- YKK Anti-snag zip insert and anti snag internal zip guard
- YKK zipped internal stash pocket
- Angled foot box for relaxed sleeping posture
- Left and right hand bags can zip together
- Drawcord stuffsack included
- Zipped cotton sack with water-resistant base for home storage
- Outer: 100% recycled polyamide. Lining: 100% recycled polyamide.
- Wide Mummy Shape - with proportionally designed differential cut
Sleeping Bag Size Guide

Wide Mummy | Regular | Long |
---|---|---|
Sleeping Bag Length | 215cm / 84.6 in | 230cm / 90.6 in |
Max User Height | 185cm / 72.8 in | 200cm / 78.7 in |
Internal Shoulder Girth | 160cm / 63.0 in | 162cm / 63.8 in |
Internal Hip Girth | 134cm / 52.8 in | 136cm / 53.5 in |
Internal Foot Girth | 108cm / 42.5 in | 110cm / 43.3 in |
Pack Size | 45cm x 24cm | 45cm x 24cm |




Pertex® Quantum
A soft, lightweight, windproof fabric that encourages insulation to fully loft. Highly packable and protective, it's ideal for mountain activities.




Pertex® Quantum
A soft, lightweight, windproof fabric that encourages insulation to fully loft. Highly packable and protective, it's ideal for mountain activities.




Fill Power - 650
Fill power is all about down quality, not quantity. Find out more about what fill power means for you when you're out in the mountains in cold conditions.




Fill Power - 650
Fill power is all about down quality, not quantity. Find out more about what fill power means for you when you're out in the mountains in cold conditions.




Rab Sleep Limit Explained
Need help choosing the right bag for your next adventure? This is our real-world assessment of a sleeping bag's usable temperature limit. Find out how we arrive at this rating and how you can use it to select your bag.




Rab Sleep Limit Explained
Need help choosing the right bag for your next adventure? This is our real-world assessment of a sleeping bag's usable temperature limit. Find out how we arrive at this rating and how you can use it to select your bag.




Ascent Collection
The Ascent series is designed for wild campers, adventure backpackers, and draughty Scottish bothies. Combining clever construction to optimise warmth with a generous fit, it ensures a comfortable night’s sleep for the weary mountain explorer.




Ascent Collection
The Ascent series is designed for wild campers, adventure backpackers, and draughty Scottish bothies. Combining clever construction to optimise warmth with a generous fit, it ensures a comfortable night’s sleep for the weary mountain explorer.




Fluorocarbon-Free Product
This product no longer contains fluorocarbons. Whether that’s in a DWR, on the zips, the threads or in the fabric. Find out more about how we’re cutting fluorocarbons from our gear.




Fluorocarbon-Free Product
This product no longer contains fluorocarbons. Whether that’s in a DWR, on the zips, the threads or in the fabric. Find out more about how we’re cutting fluorocarbons from our gear.